Page:Field Book of Stars.djvu/151

Rh, the genitive case of the Latin name of the constellation is given; for example, Vega is known as (α) Lyrae, meaning alpha of Lyra, Aldebaran as (α) Tauri, alpha of Taurus, etc.

The twilight hour affords an excellent opportunity of fixing the relative positions of the first-magnitude stars in the mind, for at that time they alone, save the planets, are visible.